A journey through the company‘s history

Company premises in Berlin

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Each vision starts with a first step

On 12 September 2012, the company Dr.-Ing. Max Schlötter is celebrating its 100th anni-versary. Since it was founded in 1912, the company – which is still family-run – has developed from an electrochemical research laboratory into one of Germany‘s leading specialist firms for electroplating with an international orientation. The company‘s name is derived from its founder, Prof. Dr. Max Schlötter, one of the pioneers of electro-plating in Germany at the beginning of the 20th century.

Join us on a journey through our company‘s history. Unfortunately, the history may have some gaps here and there due to the fact that, for some years, the records are incom-plete. We will supplement our review with quotes from various publications, private letters and records. Our first stop is in Leipzig.

Facility for an annual production of 2,160,000 sheets of tinplate, design and tinning process patented by Dr.-Ing. Max Schlötter.

Dr.-Ing. Max Schlötter (1878-1946)

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From Leipzig, we will move on to Berlin and then to Geislingen/Steige

At the beginning of the 20th century, Leipzig was one of Germany‘s leading industrial cities. This is also where Germany‘s first electropla-ting factory was founded in 1881: Dr. G. Langbein & Co., which merged with the company Pfanhauser from Vienna in 1907 to form Langbein-Pfanhauser Werke (LPW). Max Schlötter, who had graduated from his chemistry studies at the Technical University of Munich in 1902 and was later employed by the German Solvay Group in Bernburg (Saxony-Anhalt), subsequently worked for LPW as a chemist from 1906-1912. In 1912, at the age of 34, he quit his job and founded an electrochemical research laboratory in Leipzig. At the same time, he also received an offer to become a partner at Hanson, van Winkle & Co. in New Jersey, the oldest

electroplating company in the USA. However, Schlötter decided to stay in Germany for family reasons – at the time, his daughter was only two years old. Initially, his business operations focused mainly on the electro-plating of sheet metal, wire and metal bands. After a short stay in Cologne, his company relocated to Berlin in 1915.

During World War I, the Prussian Ministry of War commissioned Schlötter with the

procurement of metal substitutes. For the Imperial Printing House, he introduced a galvanoplastic process for the manufacture of printing plates from steel which did not require any copper. Galvanoplasty is a procedure in which electro-lysis is used to condense thick metal layers on a negative mould, thereby forming a sepa-rate object. In the printing industry, galvanos are used for the reproduction of the original printing plates.

After the end of the war, Schlötter stayed in close contact with the printing industry at home and abroad. As the political map of Europe was completely rearranged after World War I, it is not surprising that there was also an increased demand for new bank

notes and stamps. Schlötter‘s records reveal that he already had a number of international customers at this time. “After the end of the war, I focused on the marketing and technical evaluation of my processes. In Prague, I founded a facility for the production of Czech treasury notes, in Stockholm a galvanoplasty plant for the Swedish Navy for the production of nautical charts, in Finnland a printing house for the printing of treasury notes and stamps.“ (quote from the personal records of

Max Schlötter, probably from the 1930s).

In 1928, Schlötter built a large galvano-plasty plant for the production of copper galvanos for the Ullstein publishing house and, together with C. Lipp, wrote a textbook on galvanoplasty. In 1929, Schlötter was appointed honorary professor of the Faculty of Materials Science at the Technical University of Berlin. The fact that various students carried out the experiments for their dissertation in his electrochemical laboratory indicates that he must have worked together closely with various profes-sors of the Technical University of Berlin in the 1930s.Alfred Geldbach, one of Max Schlötter‘s doctoral students, became his son-in-law in 1937. In the 1920s and 30s, Schlötter also completed his groundbreaking work on the development of bright electrolytes (see below). His records and letters indicate that he was still in close contact with inter- national customers in the 1930s and often travelling abroad on business: “I would like to apologise for only responding now to your query on the lecture at the convention of the Reich Committee for Corrosion and Materials Protection; reason being that I have, in the meantime, been abroad in England, Switzer-land and Italy…“ (8.7.1935, letter by Max Schlötter to the Swedish Professor W. Palmaer)

Nowadays, it is not possible to determine exactly how many people were once employed at Schlötter. At the beginning of 1944, Max Schlötter decided to move his company away from Berlin – probably due to the increasing amount of air raids. After initially considering Pfaffenhofen as an alternative location, he then decided to instead relocate to the space offered to him by Württem-bergische Metallwarenfabrik (WMF) in Geislingen. In the last months of the war, only a few employees remained. One of them being the then 19-year-old Kurt Nemitz, who worked for Schlötter as trainee from 1944 onwards. In his autobiography from 2006, he describes the last months of the war: “The last months of Hitler‘s war con-fronted me with a number of Kafkaesque situations. I was working in Geislingen in the

Berlin laboratory

capacity of a white-coated electroplating chemist on the large premises of WMF at the obviously important laboratory of Professor Dr.-Ing. Schlötter. Nobody was interested in finding out why I, at my age, had been exempted from military service in order to work there. Together with two forced labou-rers, the well educated academics Vaclav Trcka from Czechoslovakia and André Marchal from France, we worked in the laboratory, toasted bread on Bunsen burners and tested out various galvanic methods for the silver plating of sheet copper.“ (1)

Soon after relocating to Geislingen, Max Schlötter incurred health problems and passed away in May 1946 at the age of 67 years.His daughter Ingeborg Geldbach, her husband Dr. Alfred Geldbach and Dr.-Ing. Joachim Korpiun, who had previously worked for Schlötter in Berlin, decided to rebuild the company at the new location. The industrial premises in East Berlin were expropriated in 1948. In 1962, during a speech at the company‘s 50th anniversary, Ingeborg Geld-bach explained why she had decided to rebuild the company in 1946: “A short time before my father passed away, some English-men commissioned by BIOS […] interviewed me to find out more about certain processes which my father had expert knowledge of. The English and Americans continued their interviews even after the death of my father. They showed me the importance which certain foreign countries attached to the processes which my father had developed in the area of surface plating. I was convinced that it was my legacy to maintain his life‘s work by continuing the company‘s business opera-tions under his name.“

After the Allied forces invaded Normandy in 1944, the British Intelligence Objectives Sub-Committee (BIOS) was one of the Allied forces‘ secret services responsible for docu-menting the level of development of Ger-many‘s industry and research sector.

Laboratory in Geislingen in the 1950s

(1) Quoted from Kurt Nemitz: Bundesratufer. Erinnerungen, Oldenburg 2006, p. 100.

Letters from the post-war era indicate that no decision had yet been reached on whether the company Schlötter should stay in Geislingen permanently. Old records reveal requests for business premises sent to the Municipality of Osterburken on behalf of Max Schlötter in May 1946. At the begin-ning of 1949, it was clear that Schlötter would have to leave the premises rented from WMF: “…Furthermore, we had will have to temporarily interrupt our development work. The premises which we have been using for our laboratory and business opera-tions since 1944 must be vacated by spring of the following year. Due to the lack of sui-table space, we will need to build, which is no easy task here at present“ (24.1.1949, letter by Ingeborg Geldbach to Richard Auspitzer, an American business partner, who had introduced Schlötter‘s nickel process to the USA).

The overall business development, however, was downright positive: “Business is even better than what I expected after the currency reform. There is some development work taking place at my laboratory which appears quite

promising and some work which has already led to pleasing results“ (24.1.1949, letter by Ingeborg Geldbach to H.L.W. Widmer). In the end, the company acquired its own property and moved to the new location in 1950. At the 40th company anniversary in 1952, Schlötter already had 48 employees in Geislingen. Nowadays, around 170 staff members are employed at this location. Since 1976, the company is managed by Max Schlötter‘s grandson Ulrich Geldbach. His daughter, Dr. Stefanie Geldbach, is already the 4th gen-eration of the family active in the company‘s management.The company‘s premises have been expanded continuously since 1950: an administration building was erected in 1956, a research laboratory was built in 1970, which was expanded in 1988 and the administration building was expanded in 2007. The most recent addition ensued in 2011, when a neighbouring building was acquired, which is currently being converted into a new waste-water treatment facility and a test facility for electroplating processes.

Inhouse plating shop in the 1960s

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Active globally

After having established its headquarters in Geislingen, the company Schlötter set up various international subsidiaries, the first one being the Schloetter Company Ltd, which was founded in 1969 by Ingeborg Geldbach. After initially being based in Birmingham, the subsidiary relocated to its present-day location of Pershore, a small town south of Birmingham, where it also has own laboratories and production facilities at its disposal. Apart from electroplating chemistry, the English Schlötter subsidiary also develops and manufactures industrial paints and lacquers used mostly in glass pro-duction. On the initiative of Ulrich Geldbach, further foreign branches were set up. 1976 marked the foundation of Schloetter Ireland in Newbridge, approx. 40 km southwest of Dublin. Apart from the head office in Geislingen, Schlötter Ireland is the largest production facility of the Schlötter Group. In the early years, the focus of the Irish sub-sidiary was on the electronics industry. After

the circuit board industry moved to the Far East, the necessity arose to develop new business segments, which was achieved by manufacturing new products for the medical and pharmaceutical industries.

Schloetter Ges.m.b.H in Salzburg was foun-ded in 1978 in order to facilitate the sale of chemical products and plants in Eastern Europe. In the meantime, Schloetter Austria has become one of the leading electroplating companies in Austria. In close cooperation with the German head office, the Salzburg subsidiary is constructing electroplating plants and electronic control systems. Schlötter Svenska, the Swedish subsidiary, was founded in 1980. Schlötter Svenska does not have any production facilities of its own, but successfully represents Schlötter‘s entire range of products in Sweden and Norway.

Since 1982, Schlötter is represented in Asia by Schloetter Asia. Schloetter Asia acts

solely as distributor, looking after the needs of all customers in Southeast Asia.

2004 marked the founding of a Chinese subsidiary, which is based in Wuxi near Shanghai.

Overall, the Schlötter Group is employing a staff of around 300. The six foreign subsidi-aries are supported by a close-knit distribution network: Schlötter is represented in more than 25 countries on five continents. The company‘s international orientation is also reflected in its high export ratio: in 2011, approx. 40% of its total turnover was gener-ated by exports.

Construction in the 1960s

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Chemistry: innovative electrolytes since 1912

Research has a long tradition at Schlötter, which is also indicated in the choice of name “electrochemical research laboratory“ during the company‘s foundation in 1912. In the course of his professional life, Max Schlötter registered more than 60 patents in Germany alone. Even today, around 25% of the em-ployees at the head office in Geislingen are active in research & development. Around 15% of the company‘s turnover is spent on R&D, which constitutes a very high level of research intensity.

Being a cross-sector technology, electro-plating contributes significantly to the devel-opment of new products and technologies. In the course of its 100-year history, the company Schlötter has continuously managed to position itself as a technological leader, which we would like to illustrate by means of certain especially successful processes.

Even whilst being employed at LPW in Leipzig, Max Schlötter was working on developing methods for electrolytic tinning. In 1908, he discovered that tin and lead can be deposited from phenolsulphonic acid solutions. The shortage of materials during World War I led to an increased interest in electrolytic tinning because galvanic tinning required much less tin than the hot-dipping processes used up to then. It was at this time that Max Schlötter came into contact with the tinplate industry. In 1915, he designed a fully auto-matic tinning plant for the company Remy van der Zypen (later known as Rasselstein AG). At the end of the war, however, produc-tion was discontinued. One of the problems being that the tin deposits were matt. In 1934, after many years of continuous experi-mentation, Max Schlötter finally managed to develop a process for the electrodeposition

of bright tin, patented as DRP 746134. In the same year, he constructed the world‘s first continuous tin plating facility at Rasselstein AG in Andernach, which had in the mean-time become part of the ThyssenKrupp Group. In the USA, the United States Steel Corp. put a similar continuous tin plating facility into operation in 1937, which also used the tin electrolytes developed by Schlötter. This was the beginning of the success story of tinplate as modern pack-aging material.

Tin: electrolytic tinning and the success of tinplate

Ingeborg Geldbach, beginning of the 1950s

Advertisement from the late 1960s

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CULMO: a classic from the 1960s

Bright Tin CULMO, which works on a sulphuric acid basis, was patented worldwide in 1964. CULMO was characterised by outstanding throwing power and good solderability and quickly turned into an international bestseller. Only three months after it was introduced to the market, 50,000 litres were already in use. CULMO was not only suitable for the tinning of household items, but also for use in the rapidly developing electronics industry. Already by the mid-60s, Schlötter had recognised the significance of the still young circuit board industry for the electroplating industry.

Bright Tin CULMO made it possible for Schlötter to access this increasingly impor-tant sector of application. Due to the good solderability, the tin layer enabled a stable soldering of components with the circuit

board. In circuit board manufacturing, tin electrolytes are also used as metal resists. Following the pattern plating process in the copper electrolytes, a metal is deposited which acts as etch-resist in the copper etching process. Initially, bright tin electrolytes were used for this purpose. In the 1970s, when the gaps between the conductor paths became increasingly smaller, more and more tin-lead electrolytes were used. In 1970, Schlötter introduced Tin-Lead LA to the market, which is still part of the sales programme today. However, the fluorides contained in this electrolyte led to an unwanted wastewater load. Schlötter had already identified this disadvantage in the early 1980s and began with the development of fluoride-free processes for tin-lead deposition. Apart from effecting a decrease of the wastewater load, these methanesulfonic acid based processes

also offer significant advantages in the tech-nical properties of the deposition layers, which is why they have widely replaced the fluoride-containing processes.

Even today, the development of tin and tin alloy baths is an important area of research for Schlötter. The adoption of the so-called RoHS Directive (2002/95/EC), which has led to a ban on the use of various materials (including lead) in the electronics industry, has led to the development of new lead-free processes.

Laboratory in the 1960s

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Max Schlötter was one of the pioneers in the development of modern bright and high performance plating baths. After the first chrome electrolytes were introduced in the 1920s, the interest in brilliant surfaces increased significantly. From the mid-1920s onwards, Schlötter began intensive research into the deposition of shiny metals. Apart from electrolytic tinning, he also made im-portant progress in the areas of silver and nickel deposition. US Patent No. 1 972 693 from 1932 for bright nickel, which became the basis for all available bright nickel baths for many decades, was one of his most in-fluential patents.

The new bright plating baths offered special advantages in coating systems consisting of several metal layers such as, e.g., copper-

nickel-chrome. Before workable bright plating baths were invented, the electroplated com-ponents always had to be removed from the racks, dried, polished, hung back and de-greased before being coated with a new metal. When bright plating baths were introduced, these steps of the procedure were no longer necessary. It was this which enabled the rise of automation in electroplating technology. In modern electroplating plants, the setup of a layering system such as for copper-nickel-chrome ensues within a closed process chain.

Bright nickel and other modern bright plating baths

US-Patent 1 972 693

Schlötter trade booth in the 1950s

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Zinc and zinc alloys

The galvanic deposition of zinc, which mainly serves as corrosion protection, first needed to prevail against competing procedures such as hot-dipping. The breakthrough for galvanic zinc only came in the 1930s and 1940s.

At Schlötter, the development of zinc and zinc alloy electrolytes was accelerated in the 1960s and still remains a focus of research to the present day. Initially, zinc was mainly deposited in cyanidic processes. Apart from the improvement of the technical properties such as throwing power and metal distribu-tion, the focus of research was also on the simplification of the wastewater treatment, which was made possible by no longer using cyanide or ammonium. Decisive milestones in the development were SLOTOZID (from 1968 onwards, weakly acidic, cyanide-free), ZINCASLOT (from 1971 onwards, alkaline, cyanide-free) and SLOTANIT (from 1976 onwards, weakly acidic, free of cyanide and ammonium). SLOTANIT OT, a bright zinc bath without cloud point, was added to the pro-duct range in 1986. At the beginning of 2012, the newly developed SLOTANIT OT 1010 and ZINCASLOT ZA 1020 were added to the official range of products.

By the mid-1980s, it became clear that the classic zinc processes would no longer meet the increased quality requirements of the automotive industry. Schlötter was the first

specialist company to develop zinc-nickel electrolytes also suitable for rack and barrel plating. 1987 marked the introduction of SLOTOLOY 10, a weakly acidic zinc-nickel process which had been tested successfully at VW. SLOTOLOY 10 was greeted with great interest by the automotive industry. Renault was the next manufacturer to utilise SLOTOLOY 10, other automobile manufacturers soon followed suit. In 1995, SLOTOLOY ZN 50 was the first alkaline zinc-nickel process intro-duced to the market by Schlötter. Nowadays, zinc alloy coatings are firmly established in the automobile industry.

Since the late 1980s, zinc-nickel alloys contri-buted significantly to the turnover generated by Schlötter. For many years, the alkaline processes dominated the market. In recent years, however, the weakly acidic zinc-nickel electrolytes have been experiencing a come-back. The latest products added to the product portfolio are SLOTOLOY ZN 210, a one-step alkaline process (since January 2010) and SLOTOLOY ZN 320 (weakly acidic, since August 2011), a boric acid free process which is also suitable for the direct coating of castings.

The boom of the circuit board industry also led to an increased demand for copper pla-ting processes. In the late 1960s, Schlötter worked intensively on developing acid copper electrolytes for the circuit board industry. The main focus of the research being on adapting the copper electrolytes to the continuous miniaturisation in circuit board production. The single-sided circuit board was initially followed by the double-sided board with through-holes, then by multilayer boards. The result being boards with a thick-ness of only a few millimetres, which placed high demands on the ductility of the copper during contact metallisation. In recent years, increasingly complex circuits and smaller components led to conventional multilayer circuit boards reaching their limits. They were replaced with HDI circuit boards (HDI: High Density Interconnect), which are used especially in the manufacture of smartphones, mobile phones, tablet and notebook PCs. In comparison to classic multilayer circuit boards, HDI circuit boards no longer make use of large through-holes to connect the individual circuit board layers, but use small blind holes (blind microvias) instead. Filled blind microvias make it possible to further increase the integration density. Schlötter is playing a leading role in the development of blind viafilling processes. Some of the miles-tones of the development process include processes such as SLOTOCOUP CU 140 (since 2004, plating of blind microvias), SLOTOCOUP BV 110 (since 2004, filling of blind microvias, pattern plating and the metallisation of through-holes in a single-step procedure) and SLOTOCOUP SF 20 (since 2009). The latest generation of superfilling electrolytes enables the deposition of even thinner copper coatings on the circuit board surface whilst maintaining the same filling level, thereby minimising the necessity for so-called thinning processes which would otherwise have been required for the reduction of the copper layer thickness prior to the etching of very fine conducting paths.

Copper

R&D laboratories in Geislingen/Steige

Modern electroplating plant, 2010

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Right from the start, Schlötter was not only engaged in the development and manufacture of electrolytes, but also with the conception and construction of electroplating plants. This upholds a tradition which also began with Max Schlötter. He had also registered a number of patents for plant construction, as recorded in patent documents with titles like, for example, “Galvanising apparatus for the plating of sheet metal“ (published 1923). After the company moved from Berlin to Geislingen, plant construction remained an important business segment.1951 marked the construction of the first electroplating plant in Geislingen, 1957 the construction of the first automated electroplating plant - a rotary system for the tin-plating and hot-dip coating of chassis parts. In the late 1950s, Schlötter began with the construction of a transfer automat which is still in common use today. The work programme of the first automated galvanic plant was unchangeable. Modern, electronically controlled electro-plating plants, however, can be programmed in various ways, thereby enabling the oper-ation of flexible plating programmes. SLOTRONIC-PRO®win is a variable pro-grammable control software developed by Schlötter. Its origins lie in the 1960s, when process control still used magnetic counters and relays. The first version of the modern,

Windows-based control of SLOTRONIC-PRO®win is a variable programmable control software developed by Schlötter. Its origins lie in the 1960s, when process control still used magnetic counters and relays. The first version of the modern, Windows-based con-trol of SLOTRONIC-PRO®win was introduced to the market in the late 1990s.

As was shown in the bright plating baths example, there is a close relation between developments in process chemistry and system engineering advancements in the electro-plating industry. The planning of an electro-plating plant requires a sound knowledge of the process chemistry and the respective procedural parameters. Being a specialist company for chemistry and plant construc-tion, Schlötter profits from the know-how of both of these areas of expertise. The close cooperation between the constructors and process engineers in the company ensures that the system technology is perfectly matched to the required plating process. Since the 1950s, the Schlötter Group has built more than 1,000 electroplating plants of various types. This includes small manual systems, circuit board systems and barrel and rack plating systems with a bath volume of more than 100,000 litres.

Plant construction

Rotary plant for WMF, from the late 1950sModern electroplating plant, 2010

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Summary and forecast

We have taken you on a journey through the 100-years history of Schlötter – 100 years of development in electroplating technology in which Schlötter plays a leading part.Contrary to Max Schlötter‘s assertion from 1934 – “There is so much literature on the topic of nickel plating that it is easy to believe that nothing more can be said about this type of plating“ – we at Schlötter believe that we will continue developing new electroplating technology, be it in the form of chemical advancements or innovations in plant con-struction.

Our company with its highly motivated and qualified employees, which can look back on a century of experience in electroplating, will face all future challenges.

We are proud of our 100-year history. When Max Schlötter founded his research labora-tory in 1912, it was impossible to foresee such a successful development. We are con-vinced that our company‘s founder would take pride in seeing what has become of his company.

Administration building of the company Schlötter

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Dr. - Ing. Max Schlötter GmbH & Co. KGTalgraben 3073312 Geislingen/SteigeGermanyT + 49 (0) 7331 205 - 0F + 49 (0) 7331 205 - 123info@schloetter.comwww.schloetter.com